1. Field of the Invention
This invention relates to saliva ejectors which are used to drain the oral cavity when a dental or other operation is being performed therein. More particularly, this invention relates to a disposable saliva ejector, i.e., an ejector which is discarded after having been used once.
The disposable saliva ejector according to the invention is of the type comprising a tubular stem open at both ends thereof, one end of which forms a suction inlet opening when the other end thereof is connected to a suction tube.
2. Description of the Prior Art
When a saliva ejector is applied over the lower tooth ridge of the mouth for the withdrawing of saliva from the oral cavity the suction applied to the saliva ejector may draw local portions of the soft tissues of the oral cavity into the opening or openings provided in the suction inlet end of the saliva ejector if such tissues are contacted by the suction inlet end. Thereby, the passage to the interior of the tubular stem may be obstructed at said opening or openings causing unsatisfactory functioning of the ejector. Additionally, the tissue drawing may be painful to the patient and may cause discomfortable wounds in the mouth. Especially when the suction tube connects the ejector with a central suction device which produces high vacuum there is a great risk for the tissues being drawn into the ejector.
According to U.S. Pat. No. 2,529,499 to Jankelson, issued Nov. 15, 1950 the tissue drawing in a saliva ejector is eliminated or reduced by an inlet nozzle construction comprising several individual parts which are interconnected to form a system of openings and passages in the nozzle, which admits air to the interior of the ejector to limit the degree of suction in case the suction inlet opening or openings through which the saliva shall be drained from the oral cavity when the ejector is being used should be contacted and covered by tissues and thus obstructed. The arrangement provided for this purpose in the saliva ejector disclosed in the patent referred to is constructed and designed for a saliva ejector which is intended to be used several times and to be sterilized after each use. Due to the elaborate construction thereof it is not suited to be incorporated into a disposable saliva ejector which must be produced at a reasonably low cost.